Observation of a strange region around a black hole

Einstein's theory of general relativity revolutionized our understanding of gravity in 1915. Among its many predictions, the idea that matter close to a black hole would suddenly abandon its orbit to plunge directly inward remained to be verified.


Recent observations made with NASA's NuSTAR and NICER space telescopes have finally confirmed this theory. A team of researchers from the Department of Physics at the University of Oxford conducted this study. Published in the Monthly Notices of the Royal Astronomical Society on May 16, it paves the way for new discoveries about black holes and spacetime.

The researchers used the X-ray frequency band to observe a black hole named MAXI J1820+070, located about 10,000 light-years from Earth. By analyzing the collected data, they found that the observed light came from a region where matter falls directly into the black hole.

Black holes are surrounded by accretion disks; they consume gas, stars, and even other black holes. These disks, composed of matter heated by friction, emit observable X-rays from Earth. By pointing the NuSTAR and NICER telescopes at MAXI J1820+070, the researchers detected the X-rays emitted by its accretion disk. Integrating these data into mathematical models, they discovered that the models only matched if they included light from a plunging region, thus confirming its existence.

This discovery helps us better understand the extreme gravitational fields near black holes. Observing this plunging region, located just outside a black hole's event horizon, is essential for deepening our understanding of gravity at its most powerful.

By studying more light, the researchers hope to gain unprecedented knowledge about the extreme conditions around black holes. This new observation method opens perspectives for future research and could reveal still-unknown aspects of physics.